1. Field
The field is fluid couplings, in particular connectors for use in mounting showerheads or other position-sensitive devices such as fluid couplings and pipes to threaded supply lines.
2. Prior Art
Fluid couplings are used to connect a pipe or other fluid conveying device to another pipe or utilization device, such as a showerhead or faucet. It is desirable and usually essential that such a fluid coupling be able to prevent relative rotation between the two connected devices. For example it is important that a showerhead not rotate about the axis of its water supply pipe; otherwise, water exiting the showerhead could be misdirected or the showerhead could tilt to an undesirable position. Heretofore various fluid couplings for preventing such rotation were known.
Mueller, in U.S. Pat. No. 1,512,298 (1919), shows a pipe union with corrugations on one mating face to resist rotation through the use of friction between two pipe segments.
Syverson, in U.S. Pat. No. 3,064,998 (1957), shows a coupling for a grease gun in which two facing surfaces within the coupling have teeth or serrations that prevent relative rotation of the two halves.
In U.S. Pat. No. 3,563,469 (1969), Stacey shows a spray showerhead having internal splines that are used to create a spray effect.
Williams, in U.S. Pat. No. 4,674,774 (1984), shows a coupling having rotation prevention means comprising a ring of cavities or depressions on two facing members and a ball that is placed in two mating cavities to prevent rotation.
Lipski, in U.S. Pat. No. 4,964,573 (1989), shows a showerhead adapter in which the angle of a showerhead handle can be adjusted and locked. This concept is similar to Syverson's.
Kirchner et al., in U.S. Pat. No. 5,586,791 (1995), show a push-fit, splined connector for joining a fluid supply line and a pipe in a non-rotatable manner.
In U.S. Pat. No. 6,651,939 (2000), Bischoff et al. show a showerhead holder comprising a wall-mountable bracket and a body that can be oriented as desired then locked together using mating teeth.
Mack et al, in published U.S. application 20020175519, show an anti-rotation arrangement for a submersible well pump comprising a coupling with mating teeth on facing surfaces.
In published U.S. application 20020035752, Gransow et al show a two-head shower fixture with splines that prevent pivoting of the U-tube that holds the heads.
Macan et al., in published U.S. application 20050283904, show a positionable shower arm with internal splines for locking the arm in position.
The prior-art couplings described above generally prevent relative rotation of the coupled conduits. Some of these couplings relied on friction or interfering serrations on facing surfaces, but those are prone to eventual misalignment as their frictional surface wears or if the force holding the two halves together is reduced. Other prior-art couplings relied on pressure between a washer and the shower pipe. If these were over-tightened, the washers could fail and the seal became compromised.